1. Field of the Invention
This invention relates to drawout switchgear.
2. Description of the Prior Art
When circuit breakers are mounted in cells and drawout switchgear, the breakers provide a disconnect between the line and load bus bars. As is well known, drawout circuit breakers are held in place against normal short circuits by cams which ordinarily draw the breaker into position within a cell. When very high magnetic forces occur due to high fault currents, the cams are often unable to prevent a circuit breaker from moving away from the load terminal stabs. Indeed, the magnetic forces incurred sometimes blow a circuit breaker away from the terminal stabs.
Associated with the foregoing is the occurrence of strong vibrations between the terminal stabs due to high short circuit currents. Under such conditions terminal stabs may vibrate and move sufficiently to cause arcing and other damage.